The present invention generally relates to wireless networking and, more particularly, but not exclusively, to a wireless mesh network where nodes may communicate via different communication standards such as IEEE 802.11 a/b/g/n/ac or IEEE 802.15.4 or Bluetooth standards, as well as power line communication (PLC) standards such as IEEE P1901 or HomePlug AV or G.hn (G.9960), Ethernet networks where nodes may communicate via different communication standards such as IEEE 802.3, and multimedia over coaxial alliance (MoCA) networks where nodes may communicate via different communication standards such as MoCA 1.1 or MoCA 2.0.
A wireless network consists of at least an access point (AP) and a station (STA) that is connected to this AP via its wireless interface. One of the major issues a wireless network with a single AP encounters is the limited wireless coverage area. Although wireless coverage can be increased by using a higher transmit power and/or employing lower modulation and coding schemes to improve transmitted signals' susceptibility to noise, fading and path-loss, there is still a physical limit for the coverage of a single AP due to not only regulations that restrict power emission but also physical capabilities of transceiver hardware.
Wireless networks, such as Wi-Fi networks, rely on carrier sense multiple access (CSMA) type of channel access, which means that each node first listens to, and then accesses the medium when no one is using it. In this kind of shared media, as the number of users that share the common medium is increased, per node utilization of the medium is degraded. Compare a network with two nodes, e.g., an AP and a STA, to a network with three nodes, e.g., an AP and two STAs. Whereas in the former network, STA can access the medium when it demands, thus utilizing the capacity alone, in the latter network, the two STAs have to share the medium between each other, since these two STAs cannot use the medium simultaneously.
An important point is that medium access mechanisms, such as IEEE 802.11, etc., bring protocol overhead, which degrades the overall network throughput. This protocol overhead is a result of the MAC mechanisms, such as control messaging for virtual carrier sensing, that are used to prevent collisions, i.e., unintended simultaneous transmissions by different nodes in the same carrier sense range.
Hence, it can be said that as the number of nodes that use the same communication medium increases, the amount of traffic per node is reduced. That is why, especially, networks that necessitate stringent QoS requirements carry QoS traffic on orthogonal medium, which is not shared with other traffic.